With a conventional hitch coupling, it is often necessary to back up the towing vehicle directly into alignment with the trailer so that the receiving socket of the hitch coupling on the trailer directly overlies the connecting ball of the hitch of the towing vehicle. This need arises especially when connecting a heavy trailer, as a relatively light trailer can likely be shifted manually to the required aligned position but it may not be possible to manually maneuver a heavy trailer. Misalignment requires that the towing vehicle be withdrawn and backed up again until the alignment is correct. This may require that a driver exit the vehicle a number of times to check alignment and to move forwards and backwards a number of times to complete the alignment.
To improve the ease of connecting a trailer and towing vehicle, devices have been developed to aid in achieving proper alignment between the hitch ball of the vehicle and the ball receiving socket of the trailer's hitch coupling.
U.S. Pat. No. 5,114,170 of Lannie et al. and U.S. Pat. No. 6,796,573 of Beaudoin each teach a device for connection to a trailer mounted hitch coupling to guide a vehicle carried hitch ball towards the receiving socket of the coupling. Each device features to members that horizontally converge toward the receiving socket so that the vehicle need be backed up only with enough precision to dispose the ball hitch between the members at widely spaced ends thereof. Upon further reversing, the converging members constrain the hitch ball to enter the socket situated at a narrower position along the device.
U.S. Pat. No. 4,417,748 of Dortch, U.S. Pat. No. 5,779,256 of Vass and U.S. Pat. No. 6,976,694 of Rayl et al. each teach an alignment device that similarly features horizontally converging side walls, but mounts on the towing vehicle rather than on the trailer. The side walls begin are connected forward of the hitch ball and diverge extending rearwardly therefrom so as to guide the hitch coupler on the trailer toward the hitch ball as the towing vehicle is reversed toward the trailer.
U.S. Pat. No. 4,802,686 of Isreal teaches a hitch coupling for mounting on a trailer which includes a hitch ball receiving compartment having two vertical side walls horizontally diverging away from a common end of the compartment. A generally horizontal top panel covers the ball receiving compartment and extends rearward therefrom to cover space between the side walls. The device is connected to a trailer at the wider end of the walls to support the receiving compartment and covered space between the walls forward of the trailer. In use, the towing vehicle is backed up to position the hitch ball past the receiving compartment between the side walls. The trailer is then lowered to rest the top panel on the hitch ball, the towing vehicle is driven forward and the side walls guide the moving hitch ball toward the receiving compartment. With the hitch ball received in the compartment, a pin with a lock lever is used to secure the connection by blocking withdrawal of the ball hitch.